Dogs have developed new muscles around the eyes to better communicate with people. New research to compare the anatomy and behavior of dogs and wolves shows that dogs’ facial anatomy has changed over thousands of years, especially to make them better communicate with humans.
In the first detailed analysis comparing the anatomy and behavior of dogs and wolves, scientists found that; They found that the facial muscles of both species were similar outside the eyes. Dogs have a small group of muscles that allow them to intensively raise their inner eyebrows, which are not wolves
Scientists have suggested that the internal eyebrow-raiser movement creates a reaction in humans to feed them. Because of these movements, he suggests that dogs make their eyes look bigger, more baby-like, and at the same time people think they are sorry and thus show them love.
The research team, led by psychologist Dr Juliane Kaminski, who conducted this comparative experiment at the University of Portsmouth, consisted of a team of behavioral and anatomical experts in the UK and US. This research was also published in PNAS.
“The findings indicate that dogs, after domesticated from wolves, developed a new muscle group to lift their inner eyebrows,” Dr. Kaminski explained.
“We also studied the behavior of dogs and wolves. As a result of their exposure to a person for two minutes, the dogs raised their inner eyebrows at higher and higher densities than wolves.”
“The findings suggest that this meaningful eyebrow movement in dogs may be the result of people’s unconscious preferences during domestication. When dogs make the move, it reveals a mingle of desire in humans to care for them. This will give dogs that move their eyebrows more, an evolutionary selection advantage over others, and strengthen the ‘puppy eyes’ feature for future generations.”
Dr Kaminski’s previous research showedthat dogs move their eyebrows significantly more when looking at them, compared to when people are not looking at them.
“The AU101 movement is important in the human-dog bond because it can provoke a painstaking response from people but it can also create the illusion of human-like communication,” Dr Kaminski said.
Professor Anne Burrows, the main anatomist at the University of Pittsburgh Duquesne, USA, one of the co-authors of the paper, said: “To determine whether this eyebrow movement was the result of evolution, we compared the facial anatomy and behavior of these two species, and the muscle that allowed eyebrow increase in dogs was a cluster of inadequate, irregular fibers in wolves.
“The internal eyebrow movement that rises in dogs is controlled by a muscle that does not exist in its closest livint relative the wolf.
“This is a striking difference for species that left only 33,000 years ago, and we think that remarkably high facial muscle changes may be directly linked to dogs’ enhanced social interactions with people.”
Dr Kaminski and co-author, evolutionary psychologist Professor Bridget Waller, also at the University of Portsmouth, previously mapped the facial muscle structure of dogs and called the movement responsible for a raised internal eyebrow, Action Unit (AU) 101.
Professor Waller said: “This movement makes dogs’ eyes look bigger and gives them a childish look. It can also mimic the facial movements people make when they’re sad.
“Our findings show how important our faces can be in attracting our attention and how strong facial expression can be in social interaction.”
Co-author and anatomist Adam Hartstone-Rose, of North Carolina State University in the United States, said: “These muscles are literally the thinnest muscle group you can see in them. Nevertheless, the movement provided by this muscle group seems to have such a strong effect. It also seems to be under significant evolutionary pressure. It is really noteworthy that these simple differences in facial expression helped define the relationship between the first dogs and humans. ”
Rui Diogo, an anatomy expert from Howard University in Washington DC, said: “I have to admit that I was surprised when I saw the results myself, as the gross anatomy of muscles is normally slow to change in evolution. Indeed, this change has evolved very rapidly in only a few tens of thousands of years. ”
Soft tissue fossil records, including muscle, have had a lot of difficulty reaching to date, and working with these groups on evolution is a really difficult way.
The only type of dog without muscle in the research is the Siberian Wolf, which is among the older breeds of dogs.
An alternative reason for human-dog bonding may be that people have a preference for other individuals with whites in their eyes, and intense AU 101 movements reveal the white part of dogs’ eyes.
It is not known for certain that people first brought wolves from the cold and caused them when their evolution from wolf to dog began, but this research helps us understand some of the mechanisms underlying the domestication of dogs.